<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>05_显示模式</title>
  <style>
    div {
      width: 100px;
      height: 100px;
      border: 3px solid red;
      display: block;
    }
    span {
      width: 100px;
      height: 100px;
      background-color: #0f0;
      display: block;
    }
    input,button {
      width: 100px;
      height: 100px;
      display: inline-block;

    }
    .d2:hover {
      display: none;
    }
  </style>
</head>
<body>
<div class="d1">111</div>
<div class="d2">222</div>
<div class="d3">333</div>
<span>111</span>&nbsp;<span>222</span>&nbsp;<span>333</span>
<input type="text">
<button onclick="alert(123)">12</button>
</body>
</html>